Valve mechanism for air-compressors or the like.



3 SHEETS-SHEET 1.

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Altarney PATENTED JULY 19, 1904.

A. W. &'Z. W. DAW.

APPLIOATION FILED JULY 7. 1902.

K VALVE MEGHANISM POR AIR GOMPRESSORS 0R"TH1. LIKL.v

N0 MODEL.

PATENT'ED JULY 19, 1904.

A. W. A; Z. W. DAW. VALVE MEGHANISM PoR AIRiGoMPRBssoRs 0R THB'LIKE.

APPLICATION FILED JULY 7, 1902.

3 SHEETS-SHEET 2.

N0 MODEL.

Mmm

WITNESS 5 PATENTED JULY 19, 1904. l

A. W. & Z. W. DAW. VALVE MEGHANISM EUR AIB. GOMPRESSORS 0B. THE LIKE.

APPLICATION FILED JULY 7.1902.

3 SHEETS-SHEET 3.

N0 MODEL.

IVTNESSES UNITEDV STATES Patented July 19, 1904.

PATENT OEEICEo OF LONDON.

l VALVE NIECHANISIVI FOR AIR-COMPRESSORS OR THE LIKE.

SFECIFICATION forming part of Letters Patent No. 765,359, dated July 19,1904. Application filed July '7, 1902. Serial No. 114,644. (No model.)

T 1f/ZZ whom, t muy concern.'

Be it known that we, ALBERT VILLIAMS DAW and ZAcHARiAs W ILLIAMs DAW,both subjects of thel King of Great Britain, residing at 11 QueenVictoria street, in the city of London, England, have invented new anduseful Improvements in Valve Mechanism for Air-Oompressors or the Like,of which the following is a specification.

The present invention relates to valve mechanism of the kind describedin the specification of the prior patent, No. 679,955, dated August 6,1901, granted to the above-named Zacharias Williams Daw; and it consistsin improvements in the construction of such valves and in the method ofoperating same to be hereinafter fully described.

We will proceed to describe the application of the invention toair-compressors, and as the construction and also the means of operatingthe inlet and delivery valves at both ends of the compression-cylinder(when the engine is a double-acting one) are identical a description ofthe valves at one end of such cylinder will suffice to enable theinvention to be fully understood.

In order that such improvements may be' fully understood, We willproceed to describe same by the aid of the accompanying drawings, inwhich- Figure 1 is a vertical section through one end of thecompression-cylinder and the inlet and delivery valves and valvemechanism at such end. Figs. `2, 3, and 1 are vertical sections throughthe delivery-valve and its actuating mechanism, showing certainmodilications of the arrangement illustrated in Fig. 1; Fig. 5, avertical section through the inlet and delivery valves and valvemechanism, showing a further modiiication of the arrangement illustratedin Fig. 1; Fig. 6, a plan view of a motor and air-compressor, showing asuitable manner of'meehanically actuating the slide valve or valves bywhich the inlet and delivery valves of such compressor are operated atthe required times; and Fig. 7, an end view of the inner face of thedelivery-valve. Fig.

8 represents a transverse section showing the connection of thecushioning-cylinders for the ,inlet and delivery valves of thecompressioncylinder and one form of connected mechanism for actuatingthe controlling-valve for said cylinder.

The first improvement of the present invention is illustrated in Fig. 1and consists in the arrangement for controlling the action of the piston12, mounted on the spindle 9, connected to the delivery-valve 1 of thecompressor and serving to approximately balance the difference in thepressures on the two opposite sides of such delivery-valve up to thetime when the latter begins to open, and thus avoid any great differenceof pressure in the compression-cylinder 2 above that in the receiver.For this purpose instead of connecting the forward end of the cylinder13, in which the balancing-piston 12 Works, with the rear end of thecompression-cylinder 2 by a port controlled by the compressor-piston 15,as in the ar-A rangement described in the specilication of Patent No.679,955, dated August 6, 1901, above referred to, a small pipe 18,connected with the passage 40, leading to the receiver, is arranged toconvey -air therefrom to a valvechest 46, situated outside thebalancing-piston cylinder 13. This valve-chest contains a valve which isactuated mechanically in any suitable manner to alternately open andclose communication through said pipe 18 between the passage 40 and theforward end of such cylinder 13. The valve illustrated for this purposeis a slide-valve 47, which when closed permits the cylinder 13 toexhaust through ports 100 and 51. By this means it Will bey seen thatonly the small quantity of air in front of the balancing-piston 12 willbe exhausted each time the travel of such piston is reversed, as thedeliveryevalve 1 closes instead, as in the previous patent, ofexhausting also the air contained in the passage connecting the smallpiston-cylinder 13 With the compression-cylinder 2.

1n the patent above referred to the balancing-piston cylinder 13 isdescribed as being open at its outer end; butthe same effect ofbalancing the pressures on the two sides of the delivery-valve 1 may beproduced by employing a cylinder 131 closed or practically fected by asleeve or bush 48 on the pistonrod 9. This sleeve enters the open mouthof the cylinder 13 and is slightly smaller in diameter than the saidmouth, so as to leave a certain clearance between the sleeve and theVcylinder.

Fig. 2 illustrates an arrangement in which` the outer end of cylinder 13is entirely closed and provided with means for the gradual escape undera cushioning pressure of the air at that end of the cylinder. Theslide-valve 47 when in its outward position will through port 50 placethe outer end of cylinder 13 open to the exhaust 51; but this valve willonly partially open the port 50 and will consequently partially throttlesaid port, and the air contained inthe space between piston 12 and theouter end of cylinder 13 will be confined and only be able to escapegradually through the port 50 tov the exhaust-port 51, so that it will M;exert a certain resistance or pressure upon piston 12and still furtherbuffer the deliveryvalve 1 and prevent its too violent opening. When onthe completion of the compressionstroke the delivery-valve, having beenopened, is about to close, the front of cylinder 13v will by themovement of slide-valve 47 be opened to exhaust and the port 50 from therear of Y such cylinder closed, so that as the air can-- not enterbehind the piston the pressure in the rear end ofthe cylinder will begreatly reduced,V and so establish a partial vacuum, and thus cause suchreduced pressure to act as a dash-pot to 'prevent the too violentclosing of the delivery-valve. 'It will be readily understood that byconstructing the slide-valve 47 so that -when in its outward positionport 50 will be fully open to exhaust 51 the airA will= be able toescape freely Aand practically no buffering action of the delivery-valvewill be effected thereby. Y

According vto a modification illustrated in Fig. 3 we may cause thepiston 12, controlled by the slide-valve 47, .to act as a closing-pistoninstead of a balancing-piston, as in thearrangement above described, andinthis case' the piston 7, connected to the delivery-valve l and theinner face of which is open tothe receiver-pressure, will act as thebalancingpiston. ln this form the mechanically-operated slide-valve 47.is through. the port 50v caused to place the rear of the piston 12,which it controls, alternately open to supply and exhaust while thespace in front of same only ancing-piston to the delivery-valve 1.

serves as a dash-pot by reason of any leakage from the rear to the frontof the piston, a small opening 49 being provided, if-desired, in thefront of the cylinder 13 to allow the motive Huid to gradually escapeduring the closing stroke of the piston 12. On the other hand,the piston7, connected directly to the delivery-valve 1, will, as before, bepermanently open to receive pressure from the receiver, while its rearend is now permanently open to the atmosphere, (or in successive stagecompression to the pressure of the preceding stage,) so that such piston7 will act as a bal- The area of the closing-piston in this case issoproportioned to the area of the balancing-piston as to overcome the fullreceiver-pressure on such vbalancing-piston and to allow of a sulficientmargin to rapidly close the valve. Vhen the rear of the closing-piston12 is open to pressure, it will (either alone or with the assistance ofa spring 14) overcome the pressure on the front face of thebalancing-piston 7 and the weight of the delivery-valve 1, and so closethe latter.

Accordingto a further modification the piston 12, controlled by theslide-valve 47, might be caused to serve both as a balancing-piston aswell as a closing-piston by causing said slide-valve to also control thesupply and exhaust of motive fluid to the front as well as to the rearof such piston. This arrangement is illustrated in Fig. 4 of theaccompanying' drawings, where it will be seen that the movements of theslide-valve 47 will through the ports 50 and 100 alternately place theIOO.l

rear and front of piston 12 open to supply and to exhaust 51.

A further improvement is illustratedl in Fig. 1 and relates to theinlet-valve 23, and same refers to the means whereby the rear end of thecylinder 30, in which the inletvalve-actuating' piston 29 works, isplaced open to pressure from the receiver at the required time foractuating such inlet-valve. In the prior patent this is effected by asmall slide-valve, the chest of which is in communication with thereceiver, and such valve was actuated by means of passages leading fromthe compression-cylinder to a cylinder in which worked a piston whosespindle also carried the slide-valve, said passages being controlled bythe travel of the compression-piston. A pipe led from the valve-chest tothe rear of the actuating-valve cylinder and was yalternatelyy placedopen to pressure in the valve-chest and to exhaust by movements of theslide-valve when actuated.

According to the present improvements the slide-valve 34 is arrangeddirectly upon the actuating-valve cylinder 30 and actuated by anysuitable mechanical means.

seen that the movements of slide-valve 34 will through the ports 53 and54 place the rear of the actuating-piston 29 alternately It will be pento supply and exhaust. Thel same mechanical means might be employed foractuating the slide-valve 34 of the inlet-valve 23 as are used foractuating the slide-valve 47 of the delivery balancing-piston 12, sothat the same means will serve for both purposes. A suitable arrangementfor this purpose is illustrated in Fig.- 6 of the drawings, where itwill be seen that the crank-shaft 55 of the motor 56, which actuates thecompressor, carries a helical wheel 57, gearing with a correspondingwheel 57 on a counter-shaft 58, upon which is mounted a Worm 59,engaging a pin 60 on a pivoted lever 61, the opposite end of whichengages the space between two collars 61a upon a rod 62 capable ofsliding' longitudinally in bearings and having 'tappets 63 64 and (whenthe compressor is double-acting) 63 and 64, which actuate other pivotedlevers 65 and 65,l the other ends of which are connected either to therod of the slide-valve 34 or of the slide-valve 47. The pivots 70 7 0 ofthe levers 65 65 are mounted to turn in their bearings with such leversand, as shown .in Figs. 6 and 8 and in broken lines in Fig. 1,

areA extended so as to carry another lever 71, (one at each end of thecompression-cylinder when the engine is double-acting,) which actuatesthe slide-valve of the other compressorvalve, (the inlet or deliveryvalve, as the case may be,) whereby both slide-valves will besimultaneously operated in the manner described by the same mechanism.The lever 71 is secured-to therupper end of pivot 70, so

as, like lever .65, to turn with the latter. Consequently when the lever65 is operated by the tappets 63 64, as described,` the slidevalve 34 ofthe inlet-valve will be actuated simultaneously with'the slide-valve 47of the delivery-valve; but as these inlet and delivery valves open inoppositeV directions the eect will be thatone of same will be opened andthe other closed, and vice versa. In Fig. 6 the inlet-valves aresupposedv tov be removed, as the singleYslide-valves for operating thepistons of both the deliveryand the inlet valves at opposite ends of thecompression-cylinder are supposed to be applied to the cylinder of thepistonA or' the deliveryvalves. The valve-chest of slide-valve 34 may beconnected either directly with the receiver or, as shown in Fig. l, bymeans of pipe 66 through the valve-chest oi' the deliverybalancing-piston 12.l

By the means above described an economyV is effected in the consumptionot' the compressed air necessary for opening and closing theinlet-valve.

Instead or' employing a separate slide-valve 34 and 47 and valve-chestfor the closing-pistons of the inlet and delivery valvesl and 23.l

respectively, a single valve and valve-chest only might be employed andmounted upon the cylinder of either of such closing-pistons, while oneor both ends of the cylinder of the other piston would be connected by asuitable supply and exhaust to both piston-cylinders. By this means,besides abolishing one slidevalve and valve-chest, the mechanism foroperating such extra slide-valve would be done away with. A suitablemethod of carrying this into effect is illustrated in Fig; 5 of theIdrawings, in which the single slide-valve 47 is shown as applied to thecylinder 13 o1' the lbalancing or closing piston 12 of deliveryvalvev l,while the rear end of cylinder 30.01 the closing-'piston 29 ofinlet-valve 23 is through pipe 66 connected with a port 67, formed inthe valve-chest of valve 47, so as to be placed alternately open :tosupply and to exhaust through port 51, such valve 47 also serving toplace the front of piston 12 alternately open to supply and exhaustthrough port 100.

Afurther improvement consists in introducing a buffering arrangement onboth the delivery and inlet valve spindles-9 and 28, so as to absorb anyshock on the closing ot`such valves 1 and 23, the arrangement which isillustrated in Fig. 1 being the same for both valves and consisting,broadly, in mounting on each `of the spindles 9- and 28 a sliding sleeve68 or 568, which is acted upon by the spring 14 or `24, which serves toclose or in assisting to close the valves 1 and 23, respectively, suchsleeve acting in conjunction with fixed buffer-stops 69 or 69", Figs. 1and 6, arranged in any suitable position and with which the sleeve 68 isbrought into contact when the valve closes. gland of spindle 28 ofinlet-valve 23,acts as a buffer in limiting the forward movement of. thesleeve 68 on the opening of the valve. A-

bufferingarrangement may be employed to prevent a violent jar or shockwhen thedelivery-valve 1 in opening arrives at the limit of its openingmovement. may be carried out in various ways-as, for

example, by forming a collar or enlargement on any suitable part of thespindle 9,.connect ed to such valve and carrying the closing andbalancing pistons 7 and 12, and providing a recess in a fixed partthrough which the spindle works, so that when the valve opens the collarwill enter such recess and imprison air between such collar and thebottom of the recess. Fig. 3 of the drawings illustrates one method ofeifecting this, in which the ,collar`72 is Another iixed stop 99 on theIOO Such arrangement 1v1 ov formed on the inner end of piston 7 and whenY the delivery-valve 1 opens'is caused to engage the recess 73 in thepiston-cylinder 8.. Another method of effecting this is that shown inFig. 2 and which consists in giving -suliicient lead to the slide-valve47, controlling the piston 12, for balancing or for closing (as the casemay be) thedelivery-valve 1, so as to insure` a certain quantity ofmotive iiu'id remaining imprisoned behind the piston 12 on its backwardstroke in its cylinder. It will, however, be readily understood that anyother suitable arrangement may be employed for producing the desiredbuifering effect for the opening movement oi' said delivery-valve.

The last improvement relates to the formation of the delivery-valve 1 insuch a way as tov direct the air in an outward direction all roundthrough the delivery-orifice between the air-compressor cylinder and thepassage leading to the receiver, so as to prevent or reduce the eddyingmotion of the air., which diminishes the efficiency of the compressor.This feature of the invention is illustrated in Figs. l to 5, inclusive,and Fig. 7 of the drawings, and consists in forming upon the inner faceof the valve a surface or surfaces i, such surfaces, as shown, beingconcaved from the top backward to the y'bottom and from near the edgesbackward toward the face of the valve and projecting inward through thevalveseat opening, so that the air in passing through the latter whenthe valve is open will irnpinge and be directed outward round saidopening. What we claim as 4our invention, and desire to secure byLetters Patent, is-

^ l. The combination of `a compression-cylinder, la 'delivery-valveopening ontw-*ard therefrom and having its rear face exposed to thepressure in the receiver, a cylinder open at' its inner end to thepressure in the receiver, a spindle provided with a piston on its innerend adapted to work in said 'cylinder` means connecting said piston withsaid valve, aspring for closing said valve, 1a `second piston mounted onsaid spindle, a cylinder in which `said last-mentioned piston works, avalve governing the supply and exhaust of the cylinder for the secondpiston, a pipe leading from 'the receiver to't'he valve-chest of saidgoverningvalve, and means controlled by said governing-valve 'forbuffering the stroke of the sec'- ond piston.

The-combination of a compression-cylinder, a d-eli'veryvalve openingoutward therefrom and having its rear face exposed to the pressure inthe receiver, va-cylinder open at its inner end to `the pressure in thereceiver vand at its outer end tothe atmosphere, a spindle provided withfa piston on its inner-end adapted to work in said cylinder, nieansconnecting said piston with said valve, Va lspring for closing saidvalve, a second piston mounted on said spindle, a cylinder in whichsaidsecond piston works, Ia valve Igoverning `the supply and Iexhaust ofthe cylinder for :the second piston., a pipe leading from the receiverto the valvechest of said governing-valve, and means for mechanicallyactuating said valve.

3. The combination of a compression-cylinder, a-delivery-valve openingoutward therefrom and having its rear face exposed to the pressure inthe receiver, a minor cylinder open at its inner end to the pressure inthe receiver and provided with an annular recess at said end, a pistonadapted to work in said cylinder and provided with a collar adapted toenter said recess, and mean-s for connecting :said piston with said`delivery-valve.

4. The combination of a compression-cylinder, fa delivery-valve openingoutward therefrom and having its rear face exposed to the pressure inthe receiver, acylinder open latits inner end to the pressure in thereceiver, a spindle provided with a piston on its inner end adapted towork in said cylinder, means connecting said piston with said valve,'aspring for closing said valve, a second piston mounted on `saidspindle, a cylinder in which said last-mentioned piston works, a valvegoverning the supply and exhaust ci' the cylinder for the secondpiston., a pipe leading from the receiver to the valve-chest of saidgoverningvalve, a lever for actuating said governingvalve, a slide-rodengaged by `said lever, a

shaft provided with :a worm, :a lever engaging said slide-rod andactuated by `said worm, and means for driving ysaid worm-shaft.

v5. The'cornbinationoi' a compression-cylinder., an inl et-valve openinginward to the cornpressi-on -cylinder, fa delivery -valve openingoutwardly vfrornsaidcornpression-cyiinder and having its rear faceexposed to the pressure in the receiver, pistons connected with lsuchVdelivery and inlet valves, auxiliary cylinders in which said pistonswork., a valve-chestmcunted on 'one of said auxiliary cylinders and:connected with said receiver, means for connecting said valve-chestwith the other auxiliary cylinder i'or operating the piston therein, avalve in said valve-chest, and means for mechanically `actuating saidvalve.

'6. 'The combination with the inlet :and also the delivery valve of anair-compressoroi' two valves mounted lrespectivelyon'e upon each of theycylinders of two pistons connected respectively with said iniet anddelivery valves and IOO the rneans for 'actuating lt'hese `two valves bytwo subscribing witnesses.

LBERT WHIIJIMIS DW, ZACHARIAS WILMMS BAW. Witnesses:

Fenna. Joints, HARRY A. Mohnrmn.

ITO

